Electroless plating-induced morphology self-assembly of free-standing Co–P–B enabling efficient overall water splitting

Precisely controlling the morphology of electrocatalyst which is critical to its activity and stability remains a key challenge toward efficient overall water splitting. Herein, a distinct temperature-dependent structure modulation effect of electroless plating technique is reported and consequently several bifunctional electrocatalysts with various structures are developed. The optimized bifunctional electrode with cobalt-phosphorus-boron nanoflowers growing on the carbon cloth demands overpotentials of only 91 mV and 294 mV to achieve a current density of 50 mA cm −2 for the hydrogen evolution reaction and oxygen evolution reaction in 1.0 M potassium hydroxide at 25 °C. Moreover, an overall water-splitting device assembled by this electrode can also work at high temperature of 60 °C with excellent long term durability and achieve a current density of 20 mA cm −2 at a cell voltage of around 1.39 V. This work uncovers some structure design principles of highly active electrocatalyst and provides a versatile strategy for structure modulation of the electrocatalyst for pratctical water electrolysis.